infraspinatus muscle (anatomy)

Last reviewed 01/2018

Infraspinatus is one of the muscles of the scapular region. Triangular in shape, it is one of the rotator cuff muscles. It originates from the infraspinous fossa of the scapula and the fibrous intermuscular septa. It passes laterally to insert into the middle facet of the greater tuberosity of the humerus and the fibrous capsule of the shoulder joint.

Infraspinatus is innervated by the suprascapular nerve (C5,C6).

It acts to:

  • laterally rotate the humerus at the glenohumeral joint
  • stabilize the shoulder joint